Assist Device with Standing Aid for Adding to a Wheelchair, a Wheelchair Integrated with such an Assist Device and Method for Manufacture Thereof

ABSTRACT

The disclosure relates to an assist device which can be coupled to a wheelchair.

The invention lies in the field of wheelchairs provided with a standingaid. Such wheelchairs are provided with a mechanism for moving awheelchair user to a standing position. Such a standing aid makes itpossible for the user of the wheelchair to perform tasks for which astanding position is required. It is possible here to envisage taking aproduct from a high shelf in the supermarket or reaching up to areception desk.

Wheelchairs provided with a standing aid are known in practice. Thesewheelchairs have the drawback that the freedom of movement of thewheelchair user is limited by the construction used.

An object of the invention is to obviate or reduce the above problem andenable a standing position of the wheelchair user.

This object is achieved and with the assist device which can be coupledto a wheelchair comprising a frame with a seat, rear wheels and frontwheels, which assist device comprises:

an auxiliary frame with coupling means for coupling the auxiliary frameto the wheelchair;

a sitting surface for placing on the seat of the wheelchair, whichsitting surface is mounted on the auxiliary frame for pivoting around afirst substantially horizontal pivot axis such that the sitting surfacecan be moved from a substantially horizontal sitting position to araised standing position, and vice versa;

spring means which act between the auxiliary frame and the sittingsurface and urge the sitting surface to its standing position;

locking means which can be released by means of a manual control andwhich hold the sitting surface in the sitting position; and

a support arm with a first and a second end zone, the first end zone ofwhich comprises a handle and the second end zone of which is mounted onthe auxiliary frame for pivoting around a second substantiallyhorizontal pivot axis, and the support arm can be moved from a downwardfolded position, in which the first end zone is situated on a first sideof the sitting surface, to an upward folded position of use in which thefirst end zone is situated on a second side of the sitting surface, andvice versa.

The assist device can be coupled releasably to a wheelchair. Existingwheelchairs can hereby have an assist device added thereto which cancarry the wheelchair user from a sitting position to a standingposition. A further advantage is avoiding a wheelchair user having topurchase multiple wheelchairs for different purposes. The standingfunction is advantageous in many situations, although it is alsopossible to envisage situations in which this function is notimmediately necessary, such as during a walk or in an adapted home.Depending on the situation, the assist device is coupled to or uncoupledfrom a wheelchair. In this way the additional weight of the assistdevice is only added to the wheelchair for those situations where thestanding function is actually required.

In order to couple the assist device to a wheelchair the sitting surfaceis placed on the seat of the wheelchair. The auxiliary frame is coupledto the wheelchair by means of the coupling means. There are for instancecoupling means for coupling to a footrest of the wheelchair and/orcoupling means for coupling to the frame of the wheelchair.

When the assist device is coupled to the wheelchair, the free outer endof the support arm, i.e. the first end zone, is situated in the downwardfolded position substantially under the seat of the wheelchair,preferably at the position of the feet of the user. The free outer endis preferably situated in a position such that a wheelchair user cangrip the support arm by leaning forward. In the position of use the freeouter end of the support arm is situated above the seat of thewheelchair, whereby the wheelchair user can support on the support arm.

The support arm being pivotable prevents the support arm forming anobstacle to the user when the support arm is not in use. Particularlythe left and right-hand side of the seat, i.e. the sides adjacent to therear wheels of the wheelchair, are free of obstacles. The wheelchairuser can hereby move laterally into or out of the wheelchair, this beinga usual way of moving to and from for instance a bed, car or toilet.

Tests carried out by wheelchair users have shown that it is perceived aspleasing that it is possible to take up a different position using theinvention. This moreover helps to prevent decubitus. It has also beenfound that the invention makes it easier to put on outer clothing, suchas a jacket, from a wheelchair.

The manual control is preferably situated on the handle. The manualcontrol for instance comprises a handgrip, such as known from thehandbrake of a cycle.

The handle can for instance be folded away such that it takes uprelatively little space.

In a preferred embodiment according to the invention the auxiliary framecomprises an upright which is displaceable between a raised position, inwhich the upright is situated some distance from the ground, and alowered position in which the upright touches the ground.

This achieves that movement of the wheelchair is blocked. The uprightfunctions as a type of brake. The stability of a wheelchair providedwith the assist device according to the invention is hereby increased.

The upright preferably comprises a foot on its end zone directed towardthe ground during use. This can for instance be a square foot plate oran elongate foot plate, or a tubular foot. The foot for instancecomprises aluminium, steel, wood and/or rubber. It is moreover possiblefor such a foot to comprise an elongate element which is provided at itsouter ends with elements protruding in the travel direction of thewheelchair. Such a foot can increase the stability.

In a further preferred embodiment according to the invention the uprightextends in the lowered position so far relative to the frame of thewheelchair that the front wheels of the wheelchair are situated abovethe ground when the assist device is coupled to a wheelchair.

The stability of a wheelchair provided with the assist device is herebyincreased further when the upright is in the lowered position. Becausethe front wheels of the wheelchair are lifted from the ground, they areprevented from starting to roll.

In a further preferred embodiment according to the invention the uprightis positioned substantially centrally relative to the rear wheels of thewheelchair when the assist device is coupled to a wheelchair.

Owing to the central positioning of the upright it forms a triangularbase with the rear wheels of the wheelchair. The stability of thewheelchair when the upright is in the lowered position is hereby furtherincreased.

The upright is preferably positioned such that, when the assist deviceis coupled to a wheelchair and the upright is in the lowered position,the upright is situated substantially in a zone lying in front of thefront wheels of the wheelchair in the travel direction. This furtherincreases the stability of the wheelchair during standing up.

In a further preferred embodiment the upright is coupled to the supportarm such that the upright is displaceable between the raised positionand the lowered position by moving the support arm from the downwardfolded position to the upward folded position of use.

When the user moves the support arm from the downward folded position tothe upward folded position of use, the upright is hereby carried to thelowered position. The support arm and the upright are for instancecoupled by means of an eccentric.

This achieves that in one movement the support arm can be brought to theposition of use and the upright to the lowered position.

In a preferred embodiment the spring means comprise a gas spring,preferably a gas pressure spring.

A gas spring has diverse advantages. A gas spring is a completely closedsystem and, other than for instance helical springs, is inherently safein the sense that users can never be injured by getting caught thereon.A gas spring has the further advantage that its spring force, theso-called extending force, is substantially constant over the wholerange of the gas spring.

The force required from the gas spring depends on numerous factors,including the weight of the user and the distance to the point ofrotation. In a currently preferred embodiment a gas pressure spring witha force of 2500 N is applied.

In a preferred embodiment according to the invention the assist devicecomprises means for fixing the legs of the user relative to the frame ofthe wheelchair.

Possible shifting of the user is hereby prevented, and a safe standingfunction is thus realized. The means are preferably embodied as a strapwith which the legs of the user can be fixed at knee height.

In a preferred embodiment the length of the support arm is adjustable.

This is for instance realized as a telescopic arm. This achieves thatthe length of the support arm can be adapted to the user and to thewheelchair.

In a preferred embodiment according to the invention the manual controlmeans are embodied as at least one squeeze handgrip which is added tothe handle and connected via a transmission element to the locking meanssuch that when the squeeze handgrips are squeezed the locking means arereleased.

The transmission element is preferably a bowden cable.

In a preferred embodiment according to the invention the assist devicecomprises a releasable support arm lock which is adapted to lock thesupport arm in the downward folded position and/or the upward foldedposition of use.

This achieves that the support arm can be locked so that it cannot bemoved unintentionally. This increases the safety and the convenience ofuse.

In a preferred embodiment according to the invention the angle formed inthe standing position by the sitting surface relative to the sittingposition is adjustable and/or the angle formed in the sitting positionby the sitting surface relative to a horizontal plane is adjustable.

This achieves that the angle of the seat is adjustable relative to ahorizontal position in the upper and/or lower end position. This ispossible for instance by means of an adjusting nut.

It is for instance also possible to bound the angle of the seat by meansof a belt under the seat.

The measures from the described embodiments can be combined in anydesired manner.

The invention further relates to a wheelchair with which an assistdevice according to any of the foregoing claims is integrated.

The same advantages and effects apply for such a wheelchair as describedfor the assist device. In such a wheelchair the sitting surface of theassist device can be integrated with the seat of the wheelchair, i.e.they can be embodied as one element.

Finally, the invention relates to a method for manufacturing an assistdevice or a wheelchair as described above.

Such a method has the same advantages and effects as described for theassist device and the wheelchair.

Further advantages, features and details of the invention are elucidatedon the basis of preferred embodiments thereof, wherein reference is madeto the accompanying drawings.

FIG. 1A shows a schematic perspective view of a wheelchair provided withthe assist device according to the invention, with a user;

FIG. 1B shows the wheelchair of FIG. 1A where the user has moved thesupport arm to a position between the downward tilted and upward tiltedposition;

FIG. 1C shows the wheelchair according to FIGS. 1A and 1B where thesupport arm is in the upward tilted position;

FIG. 1D shows the wheelchair according to FIGS. 1A, 1B and 1C where thesitting surface has been moved to a raised standing position;

FIG. 2 shows in detail a perspective view of the assist device accordingto the invention wherein several elements of a wheelchair are shown withbroken lines;

FIG. 3 shows a partial cross-section of the assist device according toFIG. 2.

Wheelchair 2 (FIG. 1A) is suitable for a user 4. Wheelchair 2 isprovided with assist device 6 according to the invention. Assist device6 comprises a central steel frame 7 which is provided with a support arm8 with a handle 10.

User 4 can grasp support arm 4 at handle 10 and move it upward indirection P (FIG. 1B) and downward in direction Q. Upright 12 isdisplaced from a high position to a lowered position by moving thesupport arm in direction P.

When support arm 8 has been tilted wholly upward, upright 12 is situatedin the lowest position. Foot 14 (FIG. 1C) of upright 12 makes contacthere with the ground. Front wheels 15 of the wheelchair are thenpreferably situated above the ground.

The assist device for instance comprises a releasable support arm lock(not shown) with which support arm 8 can be locked in the upward and/ordownward tilted position. The support arm lock can for instance beembodied as a resilient pin. This pin is for instance operated by meansof a lever at the handle. The pin can be provided in column 7 and lockrotating part 46.

Handle 10 comprises a squeezable handgrip 18 which can operate, i.e.release or lock, gas pressure spring 20 by means of bowden cable 16.Seat 22 (FIG. 1D) can hereby be carried to a raised standing position bygas pressure spring 20.

Because rear wheels 26 form a triangular base with upright 12, a stableposition is obtained.

Assist device 6 is coupled to the wheelchair by means of hook 28 (FIGS.2, 3) which can be suspended from protrusion 30 of the wheelchair. Sucha coupling is also applied in handcycles, whereby the invention requiresno separate coupling means on the wheelchair. A strap for fixing thelegs of the user can be fastened to the assist device by means offastening 29.

Protrusion 30 for instance comprises a clamp, bolt or other fasteningmeans for fastening hook 28 to the wheelchair.

Alternatively, the assist device is coupled to the wheelchair by meansof coupling to the vertical part of the tubes situated on either side ofthe legs of a wheelchair user (not shown).

Two strips of velcro tape 23 are arranged on the upper side of seat 22for the purpose of attaching a cushion to the seat.

On the underside of frame 7 assist device 6 is coupled to wheelchair 2by means of a coupling to rod 34 which forms a footrest of wheelchair 2.A star grip 36 is screwed for this purpose into holes 40 of plate 38which are provided with screw thread, plate 38 being connected to rod34. Gas pressure spring 20 is connected to frame 7 by means ofconnecting pieces 42, 44. Connecting piece 42 is rotatable around thesame shaft 45 as support arm 8.

Gas pressure spring 20 has a pressure force of 2500 N. Arranged aroundshaft 45 is drum 46 to which eccentric rod 48 is coupled at point 50.Rod 48 is coupled on the underside to upright 12 at point 52. Thisachieves that, when support arm 8 is moved, upright 12 displaces from araised position to a lowered position, or vice versa.

The angle of seat 22 can be adjustable, for instance by arranging thesuspension of the gas spring in adjustable manner on the frame.

The invention is by no means limited to the above described preferredembodiments thereof. The rights sought are defined by the followingclaims, within the scope of which many modifications can be envisaged.It is thus possible for instance to apply a gas spring with a greater orsmaller pressure force.

1. An assist device comprising: an auxiliary frame with coupling meansfor coupling the auxiliary frame to a wheelchair frame; a sittingsurface for placing on a wheelchair seat, wherein the sitting surface ismounted on the auxiliary frame and pivotable around a firstsubstantially horizontal pivot axis such that the sitting surface can bemoved between a substantially horizontal sitting position and a raisedstanding position; spring means which act between the auxiliary frameand the sitting surface and urge the sitting surface to the raisedstanding position; locking means which can be released by means of amanual control and which hold the sitting surface in the sittingposition; and a support arm with a first and a second end zone, thefirst end zone including a handle and the second end zone being mountedon the auxiliary frame so as to be pivotable around a secondsubstantially horizontal pivot axis, wherein the support arm can bemoved from a downward folded position, in which the first end zone issituated on a first side of the sitting surface, to an upward foldedposition of use in which the first end zone is situated on a second sideof the sitting surface, and vice versa.
 2. The assist device of claim 1,wherein the auxiliary frame includes an upright which is displaceablebetween a raised position, in which the upright is situated somedistance from the ground, and a lowered position in which the uprighttouches the ground.
 3. The assist device of claim 2, wherein, when theassist device is coupled to a wheelchair, the upright extends in thelowered position so far relative to a frame of the wheelchair that frontwheels of the wheelchair are situated above the ground.
 4. The assistdevice of claim 3, wherein the upright is positioned substantiallycentrally relative to rear wheels of the wheelchair when the assistdevice is coupled to the wheelchair.
 5. The assist device of claim 2,wherein the upright is positioned such that, when the assist device iscoupled to a wheelchair and the upright is in the lowered position, theupright is situated substantially in a zone lying in front of frontwheels of the wheelchair in the travel direction.
 6. The assist deviceof claim 2, wherein the upright is coupled to the support arm such thatthe upright is displaceable between the raised position and the loweredposition by moving the support arm from the downward folded position tothe upward folded position of use.
 7. The assist device of claim 1,wherein the spring means includes a gas spring.
 8. The assist device ofclaim 3, wherein the assist device includes means for fixing legs of auser relative to the frame of the wheelchair.
 9. The assist device ofclaim 1, wherein a length of the support arm is adjustable.
 10. Theassist device of claim 1, wherein the manual control is embodied as atleast one squeeze handgrip which is added to the handle and connectedvia a transmission element to the locking means such that when thesqueeze handgrips are squeezed the locking means are released.
 11. Theassist device of claim 1, including a releasable support arm lock whichis adapted to lock the support arm in at least one of the downwardfolded position and the upward folded position of use.
 12. The assistdevice of claim 1, wherein at least one of an angle formed in thestanding position by the sitting surface relative to the sittingposition is adjustable and an angle formed in the sitting position bythe sitting surface relative to a horizontal plane is adjustable.
 13. Awheelchair comprising: a frame with a seat; rear wheels and front wheelscoupled to the frame; and an integrated assist device including anauxiliary frame with coupling means for coupling the auxiliary frame tothe frame of the wheelchair; a sitting surface for placing on the seatof the wheelchair, wherein the sitting surface is mounted on theauxiliary frame and pivotable around a first substantially horizontalpivot axis such that the sitting surface can be moved between asubstantially horizontal sitting position and a raised standingposition; spring means which act between the auxiliary frame and thesitting surface and urge the sitting surface to the raised standingposition; locking means which can be released by means of a manualcontrol and which hold the sitting surface in the sitting position; anda support arm with a first and a second end zone, the first end zoneincluding a handle and the second end zone is mounted on the auxiliaryframe so as to be pivotable around a second substantially horizontalpivot axis, wherein the support arm can be moved from a downward foldedposition, in which the first end zone is situated on a first side of thesitting surface, to an upward folded position of use in which the firstend zone is situated on a second side of the sitting surface, and viceversa.
 14. A method of manufacturing an assist device the methodcomprising: providing an auxiliary frame with coupling means forcoupling the auxiliary frame to a wheelchair frame; providing a sittingsurface for placing on a wheelchair seat, wherein the sitting surface ismounted on the auxiliary frame and pivotable around a firstsubstantially horizontal pivot axis such that the sitting surface can bemoved between a substantially horizontal sitting position and a raisedstanding position; providing spring means which act between theauxiliary frame and the sitting surface and urge the sitting surface tothe raised standing position; providing locking means which can bereleased by means of a manual control and which hold the sitting surfacein the sitting position; and providing a support arm with a first and asecond end zone, the first end zone including a handle and the secondend zone is mounted on the auxiliary frame so as to be pivotable arounda second substantially horizontal pivot axis, wherein the support armcan be moved from a downward folded position, in which the first endzone is situated on a first side of the sitting surface, to an upwardfolded position of use in which the first end zone is situated on asecond side of the sitting surface, and vice versa.
 15. The method ofclaim 14, wherein the auxiliary frame includes an upright which isdisplaceable between a raised position, in which the upright is situatedsome distance from the ground, and a lowered position in which theupright touches the ground.
 16. The method of claim 15, furtherincluding coupling the assist device to a wheelchair, such that theupright extends in the lowered position so far relative to a frame ofthe wheelchair that front wheels of the wheelchair are situated abovethe ground when the assist device is coupled to the wheelchair.
 17. Themethod of claim 16, wherein the upright is positioned substantiallycentrally relative to rear wheels of the wheelchair when the assistdevice is coupled to a wheelchair.
 18. The method of claim 16, whereinthe upright is positioned such that, when the assist device is coupledto the wheelchair and the upright is in the lowered position, theupright is situated substantially in a zone lying in front of frontwheels of the wheelchair in the travel direction.
 19. The method ofclaim 15, further including coupling the upright to the support arm suchthat the upright is displaceable between the raised position and thelowered position by moving the support arm from the downward foldedposition to the upward folded position of use.
 20. The method of claim14, wherein the spring means includes a gas spring.